Dorothy f



(No ModeL) Y C.H. lDUNHAM, Deod. D. F. DUNHAM, Administratrix. RAILROAD TIB PLATE.

No. 469,386. Patented Peb. 23, 1892.

Ihn/ENTER: MT-NEEEEE: /W/MM/ M MW, @Wvg UNTTED STATES PATENT @Trient CHARLES II. DUNHAM, OF CHICAGO, ILLINOIS5`DOROTHY F. DUNIIAM ADMINISTRATRIX OF SAID CHARLES Il. DUNI'IAM, DECEASED.

RAILROAD-TEE PLATE.

SPECIFICATION forming part of Letters Patent No. 469,386, dated February 23, 18921.

Serial No. 384,527. (No model.)

To @ZZ whom it may concern:

Be it known that I, CHARLES H. DUNHAM, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Railroad-Tie Plates, of which the following is a specification.

This invention relates to metallic plates that are interposed between the base of a railroad-rail and the wooden tie by which the rail is supported, for the purpose of preventing the cutting of the bers of the tie by the continued vertical oscillation of the rail un-` der the weight of the rolling-stock passing over it.

My invention consists in the combination and arrangement of parts, as hereinafter described, and pointed out in the claim.

Of the accompanying drawings, forming a part of this specification, Figure l represents a perspective view of a portion of a railroadtie, a portion of the rail thereon, and my improved corrugated tie-plate interposed between the tie and rail. Fig. 2 represents an end view of the same. Fig. 3 represents a top view of the tieplate alone. Fig. t represents a modification.

The same letters of reference indicate the same parts in all the figures.

In the drawings, a represents an ordinary railroad-rail, and b represents a wooden tie, forming one of the supports of the rail and resting on the road-bed, as usual.

c represents the tieplate which constitutes my invention, said tie-plate being interposed between the upper surface of the tie and the base of the rail and secured to the tie both by the weight of the rail resting upon it and by the usual rail-securing spikes d d, which are driven through holes c c in the tie-plate into the tie, the heads of said spikes being formed, as usual or in any suitable way, to engage the iianges of the rail.

In carrying out my invention, I provide the tie-plate with a series of corrugations 2 2 2,

extending, preferably, the entire length of the plate. I prefer to so locate the plate that the corrugations will be substantially parallel with the tie l) and at right angles with the rail a, as shown in the drawings.

v The chief advantages resulting from the corrugated form ofthe tie-plate are as follows:

First, the corrugations practically reinforce the metal of the plate to such an extent that a much thinner and lighter plate can be used than if the plate were fiat. I have found by experience that a corrugated plate three-sixteenths of an inch thick will be stiffer and better adapted to resist the bending or buck ling strain to which it is subjected by the weight of the rolling-stock than a fiat plate which is five-eighths of an inch thick. A serious objection to fiat-metal tie-plates is that they have to be made of such thickness to enable them to resist the bending or buckling strain imposed upon them that each plate becomes in eect an anvil, taking the blow transmitted by the rail from the rolling-stock and indenting or pounding out the Wood of the tie. This difficulty is obviated by the employment of a thin tie-plate, which is made feasible by my improvement.

Secondly, the corrugations in the tie-plate form air-spaces between the bottom of the plate and the tie, preventing the long-cont-inued presence of moisture in the wood under the tie-plate and thus obviating the rapid decay of the wood, which is found to take place under a fiat tie-plate, the free access of air aiforded by the corrugations to both surfaces of the tie-plate also having a tendency to prevent rusting of the tie-plate.

My invention is not limited to the particular form andarrangement of the corrugations above described. If desired, the corrugations may be arranged otherwise than parallel, and in some cases the plate may be iiat on one side (preferably the upper) and corrugated only on the other side, as shown in Fig. it, this construction affording the desired air-- spaces between the tie and plate.

I am aware that it has been proposed to place a corrugated plate or chair in a groove or recess in a tie, said groove being of the width of the base of the rail and the said plate having iiat flanges extending up and over the top of the tie each side of the rail. My construction differs from this in that by having the corrugated plate entirely on the upper surface of the tie the ends of the corrugations are left open for the circulation of 'air to more readily prevent long-continued presence of moisture in the wood under the IOO plate. Furthermore, by extending-the plate base and having holes insueh extended porconsiderably beyond the sides of the rail a tions for'the reception of the spikes, as set broad bearing-surface is formed that prevents forth. I5 the rail from tending` to out. the tie. In testimony whereof I have signed my 5 I olainuname to this specification, in the presence of The Combination, with a railway-rail and two subscribingwitnesses, this '7th day of itls supporting atgsurfaeed tile, ofl a iietal March, A. D. 1891. pate interposet etWeen sait rai an tie, v A T t, said plate having oorrugations open at their CHARLES H DDNHAM lo ends, whereby air-duets are formed between \Vitnesses;

the surfaces of the plate and tie, the said S. G. METCALF, plate extending beyond the sides of the rail- GEO. F. COLWELL. 

